Magnetically controlled indicator wheel



March 22, 1966 H. M. NEESON MAGNETICALLY CONTROLLED INDICATOR WHEEL Filed March 13, 1962 S? uygLgg INVENTOR. HUGH M NEESOA/ ATTORNE Y5 This invention relates generally to the electrical art, and more specifically to a new and useful pulse activated device which is particularly adapted for digital display purposes although its utility is by no means limited there- The primary object of my invention is to provide a device which is propelled by magnetic force in response to discrete electrical impulses, and which has a detent normally holding the device against movement in the absence of such pulses while imposing no mechanical restraint upon the device during propulsion thereof.

Another object of my invention is to accomplish the foregoing in a relatively inexpensive and simple construction composed of a relatively small number of parts and which is durable and dependable in operation.

A pulse activated device constructed in accordance with my invention is characterized in one aspect thereof by the provision of a member movable through a predetermined path, the member carrying permanent magnets spaced. apart in the direct-ion of the path, an electromagnetic deten-t movable intoand out of locking engagement with successive permanent magnets and normally held in looking engagement with an associated magnet, an electromagnetic driver positioned to repel successive permanent magnets in a direction moving the member along its path, means for magnetizing the detent to a polarity repelling it out of locking engagement with the associated magnet thereby to release the member for movement along the path, and means for magnetizing the driver to a :polarity repelling an associated permanent magnet thereby to move the member along its path.

In another aspect thereof, a pulse activated device constructed in accordance with my invention is characterized by the provision of a wheel mounted for rotation uponits axis, the wheel carrying a series of permanent magnets spaced apart around its axis, an electromagnetic detent pivoted to swing into and out of locking engagement with successve permanent magnets and normally held in looking engagement therewith, an electromagnetic driver positioned to repel successive permanent magnets in a direction imparting a rotary force to the wheel, means for magnetizing the detent to a polarity repelling it out of locking engagement with its associated permanent magnet and thereby releasing the wheel for rotation, and means for magnetizing the driver to a polarity repelling its associated permanent magnet and thereby rotating the wheel.

The foregoing and other objects, advantages and characterizing features of my invention will become clearly apparent from the ensuing detailed description of one, illustrative embodiment thereof, taken together with the accompanying drawing showing the same wherein like reference numerals denote like parts throughout the various views, and wherein:

United States Patent M FIG. 1 is a somewhat schematic, side elevational view' Patented Mar. 22, 1966 Referring now in detail to the illustrative embodiment of my invention depicted in the accompanying drawing, there is shown a wheel, generally designated 1, comprising a disc 2 mounted for rotation about the axis of shaft 3, being journalled thereon by a hub 4. Disc 2 has a rim 5 around its periphery, the rim being formed by a strip of material curved around disc 2 and projecting laterally from opposite sides thereof, as clearly shown in FIG. 2. In the example illustrated, rim 5 comprises an ihdicia bearing member, as indicated at 6 in FIG. 2, and the wheel is adapted to present successive indicia to view through the window opening in panel 7 ('FIG. 1).

Wheel 1 carries a series of permanent magnets 8 spaced apart around its periphery. The magnets 8 extend through disc 2 at rim 5, whereby the magnets are supported immediately behind the rim and are carried by the disc and rim for rotation with wheel 1 about the axis of shaft 3. One end or pole of each magnet is positioned on one side of disc 2, and the other magent end or pole is positioned on the other side of the disc, with all of the magnets having the same pole on the same side of the disc.

An electromagnetic driver 9 is provided, in the form of a U-shaped armature 10 having a magnetizing coil 11. Driver 9 is mounted on a panel 12 removably secured to a support 13, the details of which can be varied and are not essential to my invention. When energized in accordance with my invention, coil 11 magnetizes armature 10 to a polarity such that it exerts a magnetic repulsion force on the adjacent permanent magnet 8. To this end, armature 10 will be magnetized with its north pole at the end of the leg alined with the north pole of the adjacent magnet 8, and with its south pole at the end of the leg alined with the south pole of the magnet, as indicated in FIG. 3.

Further, armature 10 is alined with the adjacent magnet 8, in a plane lying chordwise of the disc, whereby the magnetic repulsive force exerted upon the associated magnet 8 by the electromagnetic driver 'will ave a component producing a rotational 'force upon the wheel. Therefore, with each energization of coil 11, a magnetic field will be exerted on the associated permanent magnet 8, of a polarity to repel the magnet and thereby advance the Wheel. Impulse energization of the driver is contemplated, to produce incremental rotation of the wheel. In the illustrated example, the wheel is adapted to rotate in ten equal increments of movement, to complete a full revolution.

Normally, the wheel is held against rotation. This is done by an electromagnetic detent 14 comprising an armature 15 pivoted on a bracket 16. Bracket 16 can extend rigidly from shaft 3 if we assume that hub 4 contains bearings or like means for rotation of the disc about the shaft. Armature 15 is formed of a magnetic material, but preferably carries a non-magnetic hook part 17 for locking engagement with the adjacent magnet 8. A magnetizing coil 18 is associated with armature 15.

Detent 14 is held in locking engagement with the associated magnet 8 both by the force of gravity and by the magnetic attraction exerted on the detent armature '15 by the permanent magnet. While armature 15 is spaced away from direct contact with the magnet 8 by the non-magnet engaging part 17, a magnetic attraction on the armature still exists. The non-magnetic part 17 merely reduces the force of this attraction, to facilitate disengagement of the detent from the magnet.

When it is desired to release wheel 1 for rotation by driver 9, detent coil 18 is energized in a direction magnetizing armature 15 to a polarity such that it is repelled from the associated magnet 8. In other words, the end of the armature carying hook part 17 is magnetized to the same polarity as the end of the magnet engaged by the hook part. Since like poles repel, the detent is thereby pivoted out of engagement with the magnet, and the wheel is free to rotate.

FIG. 4 illustrates one energizing circuit arrangement, wherein the detent and driver magnetizing coils 18 and 11, respectively, are connected in series with a pulse generator 19. The pulse generator can be of any desired type, and therefore is only schematically indicate-d. When the switch 20 is closed, the energizing circuit is completed, and whenever a pulse is generated by generator 19, both coils 11 and 18 are energized, substantially simultaneously. Therefore, as driver 9 is magnetized, to repel the associated magnet 8, detent 14 is similarly magnetized and repels itself out of locking engagement with its associated magnet. The normally locked wheel 1 is thus released, automatically, for rotation under the magnetic repulsion force created by driver 9, and is completely free of mechanical restraint by the detent 14.

Pulses of very short duration are contemplated, and when each energizing pulse is terminated detent 14 will return to engage a succeeding magnet 8 and stop the wheel. Presumably, detent 14 will engage the immediately succeeding magnet 8 just repelled by driver 9, although this is not necessarily so. The return of detent 14 to locking engagement with a magnet 8 is produced both by gravity and by the force of magnetic attraction between the detent and the magnet, thereby providing a positive locking action. In this way, the wheel can be made to advance one increment, with each pulse. The driver 9 repels its magnet 8, to impart rotation to the wheel, and when the parts are properly adjusted the detent 14 will subsequently engage that magnet to stop the wheel.

Therefore, the wheel can function as a pulse counting device, and if successive indicia 6 are associated with successive magnets 8, the incremental rotation of wheel 1 will present succeeding indicia to view through the window of panel 7.

In some instances, simultaneous actuation of detent and driver may not be desired. In that event, they are provided with separate energizing circuits, although they may have a common pulse generator 19, as shown in FIG. 5. new, the separate circuits have their own switches 21 and 22, and provide for and gate operation of the device. In this situation, the driver and detent coils can be separately energized, with the wheel remaining immobile until both coils have been energized to release the detent 14 and magnetize driver 9 during the same period of time. This arrangement enables the device to function as an element of logic, in that it is not actuated until two situations, controlling switches 21 and 22, occur simultaneously. Actuation of either detent or driver, alone, will not rotate the wheel.

Also, since the device of my invention is polarity sensitive, moving only in response to magnetic repulsion and remaining fixed in response to magnetic attraction, it is possible to connect two such devices to a common pulse generator with one responding to positive and the other to negative pulses. The coils of each device can be energized either simultaneously, as in FIG. 4, or independently, as in FIG. 5, and by arranging one device so that it will repel in response to a pulse of opposite polarity to that required by the other device, the two devices can be connected so as to discriminate between positive and negative signals. The necessary rearrangement of the one device can be accomplished by rewinding the driver coil, and either rewinding the detent coil or relocating the detent on the other side of the disc, or by reversing the magnets 8.

In addition, the device can serve a memory function, through the provision of encoding sensor devices, such as the conductor strips 23, 24, which are carried by the wheel for rotation therewith. The position of the strips 23 and 24 is determined by the position of the wheel, and t y an be ar a ged to close contacts and complete circuits when the wheel assumes a particular position. Instead of conductive strips, the sensors can comprise mechanical contact making or breaking devices, or other appropriate means.

Accordingly, it is seen that my invention fully accomplishes its intended objects, providing a pulse activated device which can comprise a display wheel, and which can perform other functions through the sensor means 23, 24, the independent energizing circuit arrangement of FIG. 5, and the use of two devices responding to signals of opposite polarity. The device comprises only a relatively few parts, which are magnetically actuated. The gravity return component of detent 14- can be varied, by changing the angular position of the detent pivot. In other words, mounting arm 16 can be rotated about shaft 3 so that the detent 14 is in a more nearly horizontal position when it is in locking engagement with a magnet 8. This varies the gravitational force in the detent when in locking position, and thereby provides a means of adjustment of the operation of the device. The speed with which the detent is returned to lock the wheel against movement will determine, at least in part, the speed with which the wheel can be operated.

The electromagnetic detent release, magnetizing the detent to repel it from the magnet 8 utilizes the presence of the permanent magnets and reduces the energy required to drive the wheel. This is because the released detent provides no mechanical or frictional restraint on the wheel, as distinguished from those detent arrangements which depend upon friction or spring tension to lock the wheel.

Also, rim 5' can be made of transparent or translucent material, and a light can be positioned behind the rim on arm 16 for example for projecting an image of the indicia through the window and onto a screen, not shown. The illumination of indicia can be independent of other factors, or it can be so related to the contacts 23, 24 that the indicia will be illuminated only when the wheel assumes a certain position.

Of course, the number of permanent magnets can be varied, as can the number of drivers and detents.

Thus, it is seen that there is provided an extremely versatile device, adapted to perform display, memory and logical functions, as indicated above. While I have dis closed and described in detail only one, illustrative embodiment of my invention, that has been done by way of illustration and without thought of limitation.

Having fully disclosed and completely described my invention, together with its mode of operation, what I claim as new is:

1. A pulse activated device comprising, a wheel mounted for rotation about its axis, a series of permanent magnets carried by said wheel in spaced apart relation around said axis, an electromagnetic detent pivoted to swing into and out of locking engagement with successive ones of said permanent magnets, an electromagnetic driver positioned to repel successive ones of said permanent magnets in a direction imparting a rotary force to said wheel, said detent normally being in locking engagement with an associated one of said permanent magnets, means for magnetizing said detent to a polarity such that said detent is repelled by said associated one of said permanent magnets to pivot out of locking engagement therewith, thereby to release said wheel for rotation, and means for magnetizing said driver to a polarity repelling the associated one of said permanent magnets, thereby to rotate said wheel.

2. A pulse activated device as set forth in claim 1, wherein said detent and said driver have magnetizing coils connected in series for substantially simultaneous energization thereof.

3. A pulse activated device as set forth in claim 1, wherein said detent and said driver are arranged for independent magnetization.

4. A pulse activated device as set forth in claim 1, wherein said detent normally is held in locking engagement with said permanent magnet at least in part by the force of magnetic attraction thereof, and is moved into locking engagement with the succeeding one of said permanent magnets at least in part by the force of magnetic attraction thereof.

5. A pulse activated device as set forth in claim 1, wherein said detent is normally held in locking engagement with one of said permanent magnets at least in part by the force of gravity and is moved into locking engagement with the succeeding one of said permanent magnets at least in part by the force of gravity.

6 A pulse activated device as set forth in claim 1, wherein said detent has a non-magnetic magnet-engaging portion, thereby reducing the magnetic attraction between said permanent magnets and said detent and facilitating disengagement of the latter from the former.

7. A pulse activated device comprising, a member mounted for movement through a predetermined path, at least two permanent magnets carried by said member for movement therewith, said magnets being spaced apart in the direction of said path, an electromagnetic detent mounted to move into and out of locking engagement with successive ones of said permanent magnets and normally held in locking engagement with an associated one thereof, an electromagnetic driver positioned to repel said permanent magnets in a direction moving said member along said path, means for magnetizing said detent to a polarity such that said detent is repelled by said associated one of said permanent magnets to move out of locking engagement therewith, thereby to release said member for movement along said path, and means for magnetizing said driver to repel said permanent magnets and thereby move said member along said path.

8. 'A pulse activated device comprising, a wheel mounted for rotation about an axis, a series of permanent magnets carried by said Wheel in spaced apart relation around said axis, an electromagnetic detent normally held in locking engagement with an associated one of said permanent magnets and magnetizable to a polarity such that said detent is repelled by said associated one of said permanent magnets out of locking engagement therewith, and an electromagnetic driver operable when energized to exert a magnetic force on an associated one of said permanent magnets in a direction rotating said Wheel.

9. A pulse activated device as set forth in claim 8, wherein said driver exerts a magnetic repulsion force on the associated one of said permanent magnets.

10. A pulse activated display wheel comprising, a disc mounted for rotation about the axis of said wheel, an indicia bearing rim projecting laterally from opposite sides of said disc, a series of permanent magnets carried by said disc in spaced apart relation around said rim thereof, said permanent magnets extending through said disc and having one pole on one side of said disc and the other pole on the other side thereof, an electromagnetic detent pivotally supported to swing into locking engagement with successive ones of said permanent magnets under the influence of the combined forces of gravity and the magnetic attraction of the associated one of said permanent magnets, means for magnetizing Said detent to a polarity such that said detent is repelled by said associated one of said permanent magnets to pivot away from locking engagement therewith, thereby to release said disc for rotation, an electromagnetic driver having a U- shaped armature alined chordwise of said disc, the opposite side legs of said armature being positioned in alinement with the opposite poles of successive ones of said permanent magnets, and means for magnetizing said driver to a polarity repelling an associated one of said permanent magnets, thereby to rotate said disc.

11. A pulse activated display wheel as set forth in claim 10, together with sensor means carried by said disc for rotation therewith.

References Cited by the Examiner UNITED STATES PATENTS 2,046,977 7/1936 Sortore et al. 340-324 2,433,608 12/ 1947 Handley 340-325 X 2,827,626 3/1958 De Motte 340-324 X 2,866,109 12/1958 Watson 3l0-37 NEIL C. READ, Primary Examiner. 

1. A PULSE ACTIVATED DEVICE COMPRISING, A WHEEL MOUNTED FOR ROTATION ABOUT ITS AXIS, A SERIES OF PERMANENT MAGNETS CARRIED BY SAID WHEEL IN SPACED APART RELATION AROUND SAID AXIS, AN ELECTROMAGNETIC DETENT PIVOTED TO SWING INTO AND OUT OF LOCKING ENGAGEMENT WITH SUCCESSIVE ONES OF SAID PERMANENT MAGNETS, AND ELECTROMAGNETIC DRIVER POSITIONED TO REPEL SUCCESSIVE ONES OF SAID PERMANENT MAGNETS IN A DIRECTION IMPARTING A ROTARY FORCE TO SAID WHEEL, SAID DETENT NORMALLY BEING IN LOCKING ENGAGEMENT WITH AN ASSOCIATED ONE OF SAID PERMANENT MAGNETS, MEANS FOR MAGNETIZING SAID DETENT TO A POLARITY SUCH THAT SAID 